一种自适应收缩因子的循环平稳波束形成器

Cyclostationary beamformer of an adaptive shrinkage factor

针对常用循环平稳波束形成器收敛速度慢的问题,提出一种基于自适应收缩因子形式的对角加载方法的稳健循环平稳波束形成器.首先采用收缩因子对采样协方差矩阵进行修正然后得到估计的阵列协方差矩阵,通过求解真实协方差矩阵与估计协方差矩阵之间均方误差最小的最优问题,进而求出收缩因子的大小.最后利用循环自适应波束形成(cyclic adaptive beamforming,CAB)算法求取阵列权值.仿真过程中,用所提算法与传统的循环平稳波束形成算法在低功率干扰和高功率干扰两种条件下作对比,表明该算法在收敛速度方面具有较好的性能,并且在低采样快拍数目情况下所提算法的输出SINR也相对较高.

Focused on the problem that the common cyclostationary beamformer converges slowly,the robust cycliststionary beamformer based on the diagonal loading method with an adaptive shrinkage factor is proposed. The proposed method first utilizes the shrinkage factor to modify the sampling covariance matrix and naturally obtain the estimation of the covariance matrix. Then the shrinkage factor can be calculated by solving the optimal problem about the minimum mean square error between the real covariance matrix and the estimated covariance matrix.Finally using the cyclic adaptive beamforming（ CAB） algorithm to achieve the weighting value of the array.Simulation results show that the proposed method converges faster compared with the traditional cyclostationary beamforming algorithm when it comes to high power of interferences or low power of interferences,and outputs higher SINR under the case of low snapshot.